阅读说明：本技术 一种降低磷酸法活性炭灰分的工艺方法 (Process method for reducing ash content of phosphoric acid method activated carbon ) 是由 徐茹婷 孙康 许伟 卢辛成 王傲 孙昊 刘艳艳 陈超 于 2020-06-30 设计创作，主要内容包括：本发明公开了一种降低磷酸法活性炭灰分的工艺方法,该方法利用碱洗、酸洗、添加氧化剂的组合工艺对活性炭中难溶于水的聚合磷酸和聚合磷酸盐灰分进行深度脱除,在25-100℃振荡15-60min,通过离心脱水,得到低灰分磷酸法活性炭。该方法得到的活性炭灰分含量最低可到1％以下。本发明操作简单,易于工业化应用,通过使用常见的酸碱溶液和氧化剂,在一定温度下振荡或浸泡,提高聚合磷酸和聚合磷酸盐灰分的水解速度,通过离心脱水,最大程度地将活性炭孔道内的聚合磷酸等杂质与活性炭快速分离,有效地防止水溶性杂质的二次吸附,从而实现活性炭灰分含量的降低,为磷酸法活性在食品、医药、净水等场合的应用提供了参考和借鉴。(The invention discloses a process method for reducing ash content of phosphoric acid method activated carbon, which utilizes a combined process of alkali washing, acid washing and oxidant addition to deeply remove water-insoluble polymerized phosphoric acid and polymerized phosphate ash content in the activated carbon, oscillates for 15-60min at 25-100 ℃, and obtains the low-ash phosphoric acid method activated carbon through centrifugal dehydration. The ash content of the activated carbon obtained by the method can be below 1 percent at the lowest. The method is simple to operate and easy to industrially apply, the common acid-base solution and the common oxidant are used, the vibration or soaking is carried out at a certain temperature, the hydrolysis speed of the polymerized phosphoric acid and the ash content of the polymerized phosphate is improved, impurities such as the polymerized phosphoric acid in the pore channel of the activated carbon are quickly separated from the activated carbon to the greatest extent through centrifugal dehydration, and secondary adsorption of water-soluble impurities is effectively prevented, so that the reduction of the ash content of the activated carbon is realized, and reference are provided for the application of phosphoric acid method activity in the occasions of food, medicine, water purification and the like.)

1. A process method for reducing ash content of phosphoric acid method activated carbon is characterized by comprising the following steps: deeply removing the water-insoluble polymerized phosphoric acid and the polymerized phosphate ash in the activated carbon by using a combined process of alkali washing, acid washing and oxidant addition, oscillating or soaking in a water bath, and centrifugally dewatering to obtain the low-ash phosphoric acid method activated carbon.

2. The process for reducing ash content of phosphoric acid process activated carbon according to claim 1, wherein the alkali is any one or a mixture of sodium hydroxide, potassium hydroxide and sodium bicarbonate, and the pH is adjusted to 8-11.

3. The process for reducing ash content of phosphoric acid method activated carbon according to claim 1, wherein the acid solution is any one or a mixture of hydrochloric acid, nitric acid, oxalic acid, acetic acid and sulfuric acid, and the pH is adjusted to 2-5.

4. The process method for reducing ash content of phosphoric acid method activated carbon according to claim 1, wherein the oxidant is any one or a mixture of hydrogen peroxide, hypochlorous acid and sodium hypochlorite, and the mass ratio of the oxidant to the washing liquid is 1-5: 100.

5. The process for reducing ash content of phosphoric acid process activated carbon according to claim 1, wherein the temperature of the water bath is 25-100 ℃.

6. The process for reducing ash content of phosphoric acid process activated carbon according to claim 1, wherein the shaking or soaking time is 15-120 min.

7. The process for reducing ash content of phosphoric acid process activated carbon according to claim 1, wherein the dewatering method is centrifugation.

8. The low ash phosphoric acid process activated carbon prepared by the process for reducing ash content of phosphoric acid process activated carbon of any one of claims 1 to 6, wherein the ash content is less than 2.2%.

Technical Field

The invention belongs to the technical field of carbon material preparation, and particularly relates to a process method for reducing ash content of phosphoric acid method activated carbon.

Background

The activated carbon is a high-efficiency carbon adsorption material with developed pore structure, large specific surface area and strong selective adsorption capacity, and is widely applied to the industries of chemical industry, medicine, food, environmental protection, military and the like. The chemical method for preparing the active carbon is a method for preparing the active carbon by uniformly mixing and soaking raw materials and a certain chemical reagent for a certain time, and then carrying out the steps of carbonization, activation, washing, drying and the like. Common activators are phosphoric acid, zinc chloride, and the like. Although the zinc chloride activated carbon has high adsorption capacity, the zinc chloride activated carbon has serious environmental pollution, so that a phosphoric acid method is gradually adopted in factories to produce chemical activated carbon. China is the first major country in the world for producing the phosphoric acid method wood activated carbon, but the ash content of the produced phosphoric acid method wood activated carbon is generally high and is about 7 percent, so that the added value of the product is greatly reduced, and the application of the phosphoric acid method wood activated carbon in the occasions of food, medicine, water purification and the like is influenced. Therefore, the reduction of the ash content of the phosphoric acid method activated carbon has important significance

The main factors influencing the ash content are raw material source, phosphoric acid concentration, impregnation ratio, carbonization activation temperature and time, washing steps and the like. The active carbon deliming can be divided into three stages of an early stage, a middle stage and a later stage. The early deashing means that the raw materials are treated to achieve the purpose of removing ash, but the early deashing treatment capacity is large. The medium-term deliming refers to deliming in the preparation process of the activated carbon. The later deashing refers to the deashing after the preparation process of the activated carbon, and is the most widely adopted deashing method.

The preparation process of the phosphoric acid method activated carbon needs high-temperature activation, so that phosphoric acid is polymerized to form insoluble polymerized phosphate which is a main component forming ash of the phosphoric acid method wood activated carbon, and the ash cannot be effectively dissolved by a conventional washing method, and the activated carbon cannot be efficiently separated from the partially dissolved ash, so that the ash content of the phosphoric acid method activated carbon is higher directly.

Disclosure of Invention

The invention solves the technical problem that in the prior art, the later-stage ash removal of the activated carbon is usually carried out by only washing and soaking with normal-temperature water, the ash removal effect is poor, and the additional value of the activated carbon product is greatly reduced.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

a process for reducing the ash content of phosphoric acid activated carbon includes deep removing the water-insoluble polymerized phosphoric acid and the polymerized phosphate ash content in activated carbon by alkali washing, acid washing and adding oxidant, oscillating in water bath or immersing, and centrifugal dewatering.

The process method for reducing the ash content of the phosphoric acid method activated carbon is characterized in that the alkali is any one or a mixture of sodium hydroxide, potassium hydroxide and sodium bicarbonate, and the pH value is adjusted to 8-11.

The process method for reducing the ash content of the phosphoric acid method activated carbon is characterized in that the acid is any one or a mixture of hydrochloric acid, nitric acid, oxalic acid, acetic acid and sulfuric acid, and the pH value is adjusted to 2-5.

The process method for reducing the ash content of the phosphoric acid method activated carbon comprises the step of using any one or a mixture of hydrogen peroxide, hypochlorous acid and sodium hypochlorite as an oxidant, wherein the mass ratio of the oxidant to washing liquor is 1-5: 100.

The process method for reducing the ash content of the phosphoric acid method activated carbon has the water bath temperature of 25-100 ℃.

The process method for reducing the ash content of the phosphoric acid method activated carbon has the oscillation time of 15-120 min.

The process method for reducing the ash content of the phosphoric acid method activated carbon adopts a centrifugal dehydration mode.

The ash content of the low-ash phosphoric acid method activated carbon prepared by the process method for reducing the ash content of the phosphoric acid method activated carbon is lower than 2.2 percent.

Advantageous effects

(1) The method is simple to operate and easy for industrial application.

(2) The invention improves the hydrolysis speed of the polymerized phosphoric acid and the polymerized phosphate ash by using common alkali, acid and oxidant and oscillating or soaking at a certain temperature, thereby realizing the reduction of the ash content of the activated carbon.

(3) According to the invention, through centrifugal dehydration, impurities such as polymerized phosphoric acid in the active carbon pore canal are quickly separated from the active carbon to the greatest extent, and secondary adsorption of water-soluble impurities is effectively prevented, so that the ash content of the active carbon is reduced.

(4) The ash content of the activated carbon prepared by the method is low, the added value of the product is greatly improved, and reference is provided for the application of the activated carbon prepared by the phosphoric acid method in the occasions of food, medicine, water purification and the like.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with examples are described in detail below.